1. Field of the Invention
The present invention relates to the field of electronic data storage and transmission devices, and more specifically to a telecommunications terminal for use with a telephone system.
2. Prior Art
Since the advent of Touch Tone telephone dialers, i.e., telephone dialers using push buttons and which generate dual-tone frequency signals for data transmission, there have been several devices developed which can store numerous frequently used telephone numbers and which can automatically dial such numbers upon actuation by the user. However, many of the existing repertory dialers are physically large and heavy, are not conveniently hand-held, do not possess a self-contained power supply capable of supporting full function operation, and must be electrically attached to the telephone system to be operational, all of which makes portable use of the dialers impractical and often impossible.
One example of such a non-portable repertory dialer is disclosed in U.S. Pat. No. 3,430,004 issued to Edwin Shenk. In the Shenk dialer the signal output of a pushbutton keyboard is converted by a memory device into a binary code signal. Each key on the keyboard is associated with a unique four bit code and is also represented by a unique series of pulses. Contained within the device is a magnetic tape and tape drive device, adapted such that when a key is depressed, the pulses corresponding to that particular key are recorded on the magnetic tape. When a number is to be recalled from the magnetic tape, there is a conversion of the pulses stored on the magnetic tape to the binary code representing the number so that a multifrequency tone can be electrically coupled to a telephone line. Thus, the Shenk device is non-portable in that it does not have a self contained power supply, it must be electrically attached to the telephone system, and it is relatively large and heavy because it contains the magnetic tape and drive system.
One example of a portable dialer is disclosed by the Charles Edward's articles in the January and February 1976 editions of "Radio Electronics". Edwards discloses a hand held data terminal which acoustically couples dual-tone signals to a telephone line. This data terminal has a keyboard, a dual-tone signal generator, an audio amplifier and a speaker for acoustically coupling the dual-tone signals to the telephone line. The Edward's device further has the capability to store one telephone number for future use by configuring a diode network within the device. However, the Edward's terminal is limited to the storage of a single telephone number, and to reprogram this single number, the diode matrix must be physically reconfigured.
Besides the mechanical, electrical, and human factors, reasons which greatly minimize the effectiveness of the prior art repertory devices being used for portable data communications terminals, their functional organizations bring about further problems. One problem can be seen when one considers what occurs when traveling across area code boundaries with a repertory dialer which unconditionally dials the entire contents of a given telephone number storage location. To be useful in the new area code location, such devices require that the entire contents of their memory be re-entered with the area code, and number of all telephone numbers not local to the new area code, while all numbers local to the new area code must be entered with the telephone number only. Thus, each time such a device is moved from one area code location to another area code location, a complete reprogramming of the device must be performed so as to provide proper telephone dialing.
Another problem of the prior art reperatory dialing devices is the inconvenient display of the telephone numbers which they are storing. Typically, such devices will display an unbroken series of digits which corresponds to the area code and telephone number of interest. From such an unbroken display, it is difficult to extract the telephone number from all the other digits being displayed.
Yet other problems of the prior art reperatory dialing devices include their inability to store a prefix number, which may be necessary to reach an outside telephone line, for example, and their inability to provide a time delay between the dialing of the prefix number and the telephone number.
Accordingly, it is a general object of the present invention to provide an improved portable data telecommunications terminal.
It is another object of the present invention to provide an improved portable data telecommunications terminal which has the capability of storage of a plurality of telephone numbers or other numerical data.
It is yet another object of the present invention to provide a portable data telecommunications terminal which has the capability of generating audible tones corresponding to the contents of its storage for purposes of either dialing a telephone number, or, transmitting stored information of any sort.
It is yet another object of the present invention to provide a portable data telecommunications terminal which has a self-contained power system so as to continously maintain the storage of data.
It is yet another object of the present invention to provide an improved data telecommunications terminal which has a convenient display format.
It is yet another object of the present invention to provide a portable data telecommunications terminal which automatically determines whether or not to dial an area code number prior to dialing the telephone number.
It is yet another object of the present invention to provide an improved data telecommunications terminal which automatically provides a delay between an access code and a telephone number.